![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
304 lines
7.1 KiB
C
304 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* ALSA sequencer device management
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* Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
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*
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*----------------------------------------------------------------
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*
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* This device handler separates the card driver module from sequencer
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* stuff (sequencer core, synth drivers, etc), so that user can avoid
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* to spend unnecessary resources e.g. if he needs only listening to
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* MP3s.
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*
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* The card (or lowlevel) driver creates a sequencer device entry
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* via snd_seq_device_new(). This is an entry pointer to communicate
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* with the sequencer device "driver", which is involved with the
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* actual part to communicate with the sequencer core.
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* Each sequencer device entry has an id string and the corresponding
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* driver with the same id is loaded when required. For example,
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* lowlevel codes to access emu8000 chip on sbawe card are included in
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* emu8000-synth module. To activate this module, the hardware
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* resources like i/o port are passed via snd_seq_device argument.
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*/
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <sound/core.h>
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#include <sound/info.h>
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#include <sound/seq_device.h>
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#include <sound/seq_kernel.h>
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#include <sound/initval.h>
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#include <linux/kmod.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
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MODULE_DESCRIPTION("ALSA sequencer device management");
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MODULE_LICENSE("GPL");
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/*
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* bus definition
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*/
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static int snd_seq_bus_match(struct device *dev, struct device_driver *drv)
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{
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struct snd_seq_device *sdev = to_seq_dev(dev);
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struct snd_seq_driver *sdrv = to_seq_drv(drv);
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return strcmp(sdrv->id, sdev->id) == 0 &&
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sdrv->argsize == sdev->argsize;
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}
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static struct bus_type snd_seq_bus_type = {
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.name = "snd_seq",
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.match = snd_seq_bus_match,
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};
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/*
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* proc interface -- just for compatibility
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*/
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#ifdef CONFIG_SND_PROC_FS
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static struct snd_info_entry *info_entry;
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static int print_dev_info(struct device *dev, void *data)
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{
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struct snd_seq_device *sdev = to_seq_dev(dev);
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struct snd_info_buffer *buffer = data;
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snd_iprintf(buffer, "snd-%s,%s,%d\n", sdev->id,
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dev->driver ? "loaded" : "empty",
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dev->driver ? 1 : 0);
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return 0;
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}
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static void snd_seq_device_info(struct snd_info_entry *entry,
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struct snd_info_buffer *buffer)
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{
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bus_for_each_dev(&snd_seq_bus_type, NULL, buffer, print_dev_info);
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}
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#endif
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/*
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* load all registered drivers (called from seq_clientmgr.c)
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*/
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#ifdef CONFIG_MODULES
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/* flag to block auto-loading */
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static atomic_t snd_seq_in_init = ATOMIC_INIT(1); /* blocked as default */
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static int request_seq_drv(struct device *dev, void *data)
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{
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struct snd_seq_device *sdev = to_seq_dev(dev);
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if (!dev->driver)
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request_module("snd-%s", sdev->id);
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return 0;
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}
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static void autoload_drivers(struct work_struct *work)
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{
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/* avoid reentrance */
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if (atomic_inc_return(&snd_seq_in_init) == 1)
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bus_for_each_dev(&snd_seq_bus_type, NULL, NULL,
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request_seq_drv);
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atomic_dec(&snd_seq_in_init);
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}
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static DECLARE_WORK(autoload_work, autoload_drivers);
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static void queue_autoload_drivers(void)
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{
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schedule_work(&autoload_work);
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}
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void snd_seq_autoload_init(void)
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{
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atomic_dec(&snd_seq_in_init);
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#ifdef CONFIG_SND_SEQUENCER_MODULE
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/* initial autoload only when snd-seq is a module */
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queue_autoload_drivers();
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#endif
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}
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EXPORT_SYMBOL(snd_seq_autoload_init);
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void snd_seq_autoload_exit(void)
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{
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atomic_inc(&snd_seq_in_init);
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}
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EXPORT_SYMBOL(snd_seq_autoload_exit);
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void snd_seq_device_load_drivers(void)
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{
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queue_autoload_drivers();
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flush_work(&autoload_work);
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}
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EXPORT_SYMBOL(snd_seq_device_load_drivers);
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#define cancel_autoload_drivers() cancel_work_sync(&autoload_work)
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#else
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#define queue_autoload_drivers() /* NOP */
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#define cancel_autoload_drivers() /* NOP */
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#endif
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/*
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* device management
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*/
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static int snd_seq_device_dev_free(struct snd_device *device)
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{
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struct snd_seq_device *dev = device->device_data;
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cancel_autoload_drivers();
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put_device(&dev->dev);
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return 0;
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}
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static int snd_seq_device_dev_register(struct snd_device *device)
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{
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struct snd_seq_device *dev = device->device_data;
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int err;
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err = device_add(&dev->dev);
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if (err < 0)
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return err;
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if (!dev->dev.driver)
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queue_autoload_drivers();
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return 0;
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}
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static int snd_seq_device_dev_disconnect(struct snd_device *device)
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{
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struct snd_seq_device *dev = device->device_data;
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device_del(&dev->dev);
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return 0;
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}
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static void snd_seq_dev_release(struct device *dev)
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{
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struct snd_seq_device *sdev = to_seq_dev(dev);
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if (sdev->private_free)
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sdev->private_free(sdev);
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kfree(sdev);
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}
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/*
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* register a sequencer device
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* card = card info
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* device = device number (if any)
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* id = id of driver
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* result = return pointer (NULL allowed if unnecessary)
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*/
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int snd_seq_device_new(struct snd_card *card, int device, const char *id,
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int argsize, struct snd_seq_device **result)
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{
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struct snd_seq_device *dev;
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int err;
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static struct snd_device_ops dops = {
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.dev_free = snd_seq_device_dev_free,
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.dev_register = snd_seq_device_dev_register,
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.dev_disconnect = snd_seq_device_dev_disconnect,
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};
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if (result)
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*result = NULL;
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if (snd_BUG_ON(!id))
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return -EINVAL;
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dev = kzalloc(sizeof(*dev) + argsize, GFP_KERNEL);
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if (!dev)
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return -ENOMEM;
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/* set up device info */
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dev->card = card;
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dev->device = device;
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dev->id = id;
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dev->argsize = argsize;
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device_initialize(&dev->dev);
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dev->dev.parent = &card->card_dev;
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dev->dev.bus = &snd_seq_bus_type;
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dev->dev.release = snd_seq_dev_release;
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dev_set_name(&dev->dev, "%s-%d-%d", dev->id, card->number, device);
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/* add this device to the list */
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err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops);
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if (err < 0) {
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put_device(&dev->dev);
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return err;
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}
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if (result)
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*result = dev;
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return 0;
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}
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EXPORT_SYMBOL(snd_seq_device_new);
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/*
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* driver registration
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*/
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int __snd_seq_driver_register(struct snd_seq_driver *drv, struct module *mod)
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{
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if (WARN_ON(!drv->driver.name || !drv->id))
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return -EINVAL;
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drv->driver.bus = &snd_seq_bus_type;
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drv->driver.owner = mod;
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return driver_register(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(__snd_seq_driver_register);
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void snd_seq_driver_unregister(struct snd_seq_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(snd_seq_driver_unregister);
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/*
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* module part
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*/
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static int __init seq_dev_proc_init(void)
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{
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#ifdef CONFIG_SND_PROC_FS
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info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers",
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snd_seq_root);
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if (info_entry == NULL)
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return -ENOMEM;
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info_entry->content = SNDRV_INFO_CONTENT_TEXT;
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info_entry->c.text.read = snd_seq_device_info;
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if (snd_info_register(info_entry) < 0) {
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snd_info_free_entry(info_entry);
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return -ENOMEM;
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}
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#endif
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return 0;
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}
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static int __init alsa_seq_device_init(void)
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{
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int err;
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err = bus_register(&snd_seq_bus_type);
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if (err < 0)
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return err;
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err = seq_dev_proc_init();
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if (err < 0)
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bus_unregister(&snd_seq_bus_type);
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return err;
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}
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static void __exit alsa_seq_device_exit(void)
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{
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#ifdef CONFIG_MODULES
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cancel_work_sync(&autoload_work);
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#endif
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#ifdef CONFIG_SND_PROC_FS
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snd_info_free_entry(info_entry);
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#endif
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bus_unregister(&snd_seq_bus_type);
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}
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subsys_initcall(alsa_seq_device_init)
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module_exit(alsa_seq_device_exit)
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